A369919 - cp's OEIS frontend

A369919 Triangular array read by rows. T(n,k) is the number of labeled posets on [n] of rank at most one with exactly k elements of positive indegree, n >= 0, 0 <= k <= max{0,n-1}.

n	a(n)
0	1
1	1
2	1
3	2
4	1
5	9
6	3
7	1
8	28
9	54
10	4
11	1
12	75
13	490
14	270
15	5
16	1
17	186
18	3375
19	6860
20	1215
21	6
22	1
23	441
24	20181
25	118125
26	84035
27	5103
28	7
29	1
30	1016
31	111132
32	1668296
33	3543750
34	941192
35	20412
36	8
37	1
38	2295
39	580644
40	21003948
41	116363646
42	95681250
43	9882516
44	78732
45	9

[1, 1, 1, 2, 1, 9, 3, 1, 28, 54, 4, 1, 75, 490, 270, 5, 1, 186, 3375, 6860, 1215, 6, 1, 441, 20181, 118125, 84035, 5103, 7, 1, 1016, 111132, 1668296, 3543750, 941192, 20412, 8, 1, 2295, 580644, 21003948, 116363646, 95681250, 9882516, 78732, 9]

cp's OEIS Frontend

A369919 Triangular array read by rows. T(n,k) is the number of labeled posets on [n] of rank at most one with exactly k elements of positive indegree, n >= 0, 0 <= k <= max{0,n-1}.

Table of values

List of values